Patient No. 155 had a 3β,5α,6β-triOH-Gly of 159 nM. Analysis of the Frataxin gene (FXN) showed that the patient was compound heterozygous for two GAA expansions (length 75 and 101 bp), indicating a diagnosis of Friedreich’s ataxia (FRDA). This raises the question as to whether oxidation of cholesterol by ROS could play a role in the pathogenesis of FRDA, or at least, provide a marker of ROS damage.